Smelting lead and like ores and products



T. W. CAVERS.

SMELHNG LEAD AND LIKE ORES AND PRODUCTS. APPLICATION mm was. ma.

1,343,656. Patented June 15, 1920.

annex/vie:

neeessa ry will UNITED STTES THOMAS W. CAVERS, 0F COPPERI-HLL. TENNESSEE,

PATENT OFFICE.

ASSIGNOR T0 GABRED-CAVERS CORPORATION, OF NEW YORK 3e. 11. A GORPORATION OF NEW YORK.

SMELTING LEAD hitl) LIKE GEES AND PROB'UCTS.

Application filed August 9, 191$, Eteiial No,

To all whom it may coneem lie it known that I, 'lnoiuan ull-Jinn (havens, a subjert of the King f reat Britain, residing at (impel-hill, in the county of Poll: and State of TEIU'K'SSii, hare invented rertain new and useful Improvenientu in Smelling Lead and like Ores and Products, oi whit-b the following if a aperil'ii'atiiim,

.l'b v present invention has For its object to prmluee ei-onomiee in the smelting of lead ore, and products, or lead ores or produ ta (whether or not they rontain other base metals or previous metals or both), which operation is ordinarily r'arried out in a water-jacketed blast furnace.

n the ordinary proeess, lead ores and products, sueh roasted lead sull'ld or galena, together with a flux such as limestone and silieioue matter introduced into the upper part of the blast furnace, together with more or less coke. ln the ordinary methods of operating, the amount of coke depend to a considerable extent upon the (diameter of the ore and other conditions, and in praetiee a minimum quad tity of roke relative to the burden in the furnaee ie en'iployed. The ore is usually roasted or otherwise treated to eliminate most of the sulfur and the lead is largely in the form of an oxid and in reduced by the rarbon of the eoke in the rharge fed at the top of the furnace. The uilirious Inateirial and the limestone flux, together with the iron, eoinbiue to form slag and a ("on tain amount of matte or so is made, depending upon the condition of the charge and the amounts of sulfur and arsenic present. lo produce the above reaetions, heat is necessary and this has hcj retofore all been supplied by the addition of coke with the urea and fluxes at the top of the furnai'e. There is an exeess of coke added to the charge, over and above the quantity necessary to reduce the lead oxid to metallir lead, and this excess coke is burned in the lower part of the Furnace, by the oxygen in the b ast, which is introduced into the furnace through the twyers. The hurningi of this Bileess coke provides the heat to keep the slugs molten and maintain thrteiniierature at which the reactions in the furnace take p ace.

Specification of Letter's Patent.

Patented June 15 1920 11 other kinda of metallurgical operations it has been proposed to blast in fuel. This has been proposed in connection with numerous reducing proresees in Wllltfli iron oxid ore, or oxidized iron ore, is mixed with reduring, agent and flux, and heated under ICtlllllllpj renditions tor the PUIPOSQ of produring iron metal, It has also been proposed to introdure fuel with the blast through the taggers in the smelting of copper and like ores, in wbii-h the beat required for smelting is produred, partly by oxidation of the sulfur and iron in the charge, and partly, by the burning of earbonaeeous material introduced into the furnace through the twyers with the blast, my ll. S. Patent 1,259,467).

According to the present invention I in troduee, with the blast in the lower part of the furnace, a short distance above the normal slag level therein, fine coal, or other carbonaeeous fuel, but only for the aurpose of supplying the heat to maintain the reaction temperature in the furnace, by uniting with the oxygen of the blast, which fuel will then take the place of the excess eoke added with the charge at the top of the furnace in ordinary praotiee, and in. this way ell'ert an economy in the smelting of lead, Only enough eolre, according to the present invention, need be added with the Charge at the top of the furnace to effort the redurtion of the oxide of the easily reduvible metals, earth as lead. it is not neressary to previously coke the coal to be introdured with the blast at the twyers, but this roal may be and preferably is eu'iployed in its original (uneoked) z-ondition, usually as a line powder, for example, eheap soft voal. dried and pulverized.

In addition to coal, l ma add in this manner other lead-bearing: material, leadbearin; fine dust, finely divided ores earrying base or previous metals. and in some eases I may also employ tluxing agents. This of eouree, in addition to the material introdurei'l at the top of the furnaee.

In some instanres it is possible to employ other kinds of earlmnareous fuel. oil in some instances being, suitable, and this likewise may be mixed with flue dust, ore material and the like.

In the accompanying drawing-forming a part of the present s 'iecification, I have illustrated apparatus suitable for use in carrying out the process of my present invention, the View being a vertical elevation, parts being shown in section.

in said drawing, 1 represents a blast furnace of the water-jacketed type, 2 the sole plate, 3 suitable supports, and 4 one of the tuyers, of which there may be any suitable number. The dotted line 5 represents the normal slag level. 6 is the bustle pipe and 7 the twyer pipe, in which the blast is regulated by the gate or alve 8. Into some point in the air passa e, and preferably between the gate 8 an the twyer box 4 is connected a fuel supply pipe 9 leading from a hopper-bottomed receptacle or bin for introducing the coal, with or without the other materials above referred to. In the bottom of this receptacle or bin, I place a screw conveyer, the end of which enters the upper end of pipe 9 as shown at 11, which is suitably revolved, as by gear 12. The screw will keep the upper and horizontal end of the pipe filled with coal, which will prevent air from blowing out through the bin 10. Other means may be employed to prevent air from the twyer pipe blowingback through the coal pipe and bin.

in operation, coal, e. g. fine soft coal, coal slack, or in some instances coke breeze, etc, preferably crushed and pulverized, to ll 10h may be added the materials above referred to, is fed by the screw 11, into pipe 9, the end of the screw and the fine material in the convolutions thereof within the pipe 9 forming an air seal, then the said material tlou's downwardly through the sloping part of pipe 9, into the twyer iipe 7, where it is rapidly carried bythe blast into the furnace, where the coal, etc, is practically all burned in the slag-forming zone.

in the reduction of iron ores in the blast furnace, it has heretofore been proposed to blast in coal or other carbonaceous material, for furnishing the reducing agent necessary to reduce the oxids to metal. make no claim tothe introduction of fuel or any other material with the blast for the purpose of reducing the metal, but only to produce the heat necessary to maintain the temperature at which the proper reactions will take place in the blast furnace, which heat has, in practice heretofore, been supplied by. added to the charge, by the oxygen of the blast air. Excess coke may be defined as that charged to the furnace in excess of the amount theoretically necessar. for the reduction of metals such as lea In smelting, according to the present invention, I am able to securecertam advanes, namel I am able to employ low do fuel, t at is to say, cheap fuel in the orin of soft coal and the like, and if depart of the furnace,

the burning of the excess coke.

sired, I can also introduce other materials, such as those above referred to, with flu blast. The amount of coke that need be used, is materially less than that necessary for smelting in the ordinary way, and coal, :1 much cheaper material, sub-diluted for the coke so dispensed with.

In the smelting of ordinary grades of lead ores, by the old process it has been cus ternary to employ about 1:2 to nag; of (fOliQ based upon the weight of the charge in the furnace; In accordance with the present invention, I would add to the furnace charge containing such grades of ore almut f) to 12% of coke, and the amount of fine coal or, similar fuel blown in through the twycrs would amount to about to 3T5. of the weight of the charge. These proportioi'is, of course, are subject to more or less variation, depending upon the nature of thrparticular ore, flux and furnace conditions.

hat I claim is:--

1. A process of smelting oxidized lead ores or other lead-containing materials, which comprises the step of hrulii'ig a 111i.\; ture of lead oxid material and carbonaceous reducing agent, by means of the comlmstion of powdered coal introduced into the furnace with an air blast.

2. Aprocess which comprises blowing into a blast furnace containing a mixture of lead oxid material. and coke in amount sufficient to reduce the same, a blast of air carrying fine carbonaceous fuel, the amount of such air being not greatly in excess of the quan tity'necessary to burn said fine J-arbonaceous fuel so introduced, whereby the coke reduces the lead oxid. and the iii and fuel blown in furnishes the heat necessary to promote the reaction.

In'thc blast forum-c smelting of lead ores, the step of heating the charge essen tially by blasting in carbonaceous fuel, with air to burn the same, into the lower part of the furnace above the normal slag level therein, the amount of such coal being suffieient to maintain reducing conditions.

4. In the recess of smelting in a blast furnace, leat bearing ores o r products, the step of introducing carbonaceous fuel with the blast to supply the heat necessary to produce such a temperature in {the lower continuously, as will maintain the reactions between the coke and the oxids of lead and between the silica and the iron and lime, the said carbonaceous fuel being burned in the lower part of tho furnace and the coke bcingconsumcd in ti areaction betwcen the carbon it contains and the oxids of lead.

5. A process of smelting lead ores and prgoducts to produce metallic lead, which may also canry other base metals and precious metals, which process comprises the step of introducing a relati eiy small amount of cm-lmnmrenna fuvi 5* int!) flu lfifi'i'k' [)iiii u? i? HnITlCWhiii; above fhv s 00:41 so infrmlured Fumnd, whvmb Mu: qua 1, duced at the my the fun;

charge 11m v bu mt down substantially in that iuwvsmry in rouvt with the Inn and nthvr uYbL-s prvmnt to reduce the same to lhe :nviuliiv state.

In Qatimuny whereof I affix my signature.

THOMAS XV. CAVERS. 

